The row between Hugh Grant and the Daily Mail's editor, Paul Dacre, took a further turn on Wednesday, when the celebrity actor said he had uncovered evidence of misbehaviour by Associated Newspapers.

In a fresh statement published on the Leveson inquiry website, Grant said he had obtained letters contradicting several aspects of the Mail's version of the way it had tracked down and "persistently hounded" Tinglan Hong, the mother of his newly born daughter.

Mail reporters pretended to have a parcel to deliver in order to get details of a lettings agency linked to the mother's former address, according to a statement obtained by Grant.

Westminster register office also denies the Mail's claim that its staff had subsequently handed over details of the baby's birth, supplied privately by the hospital.

Grant says in his witness statement to Leveson that it could have been illegal for the register office to supply such details.

The Westminster registrar has written to him saying: "It is absolutely not our policy to release birth notification details to members of the public and to our knowledge we have not done so. Such disclosure would be likely to involve a potential breach of data protection legislation." The country's chief registrar – the registrar-general, Sarah Rapson – is to write to Westminster council "to urge them to consider undertaking a full investigation". Grant said: "This information would have formed part of Tinglan's confidential medical records."

In another area of dispute with the Mail, Grant discloses that his former lover Jemima Khan has now sworn a witness statement to the Leveson inquiry, saying the Mail on Sunday's version of how it came to print a libellous story about them could not possibly be true.

The Mail says a freelance, Sharon Feinstein, got a story purportedly emanating from Khan herself, that Grant had been having an affair with a "plummy-voiced woman" who called him on the phone. Khan says she was completely unaware of Feinstein until the story was published.

The Mail's editor is being recalled to Leveson on Thursday to be cross-examined by Grant's lawyers. This followed a belligerent performance on Monday in which Dacre admitted personally helping draft the phrase "mendacious smear" about Grant after the actor had suggested Associated Newspapers might have engaged in phone hacking.

Dacre said Grant "knew, or ought to have known, he had no proper basis for smearing our company". He said that "to ignore the truth behind the carefully manipulated images" of celebrities would "betray the readers".

A Daily Mail spokesman said: "We note that Hugh Grant has now accepted that his claims regarding information coming from the hospital were false. We stand by the statements already made to the inquiry." A witness statement detailing the paper's stance was submitted last year by Associated's lawyer, Liz Hartley.

In evidence to Leveson the director of public prosecutions, Keir Starmer, told the inquiry on Wednesday that the Crown Prosecution Service would shortly release a guidance on the prosecution of journalists. He is drawing up an interim policy on the factors to consider when deciding whether to prosecute journalists over illicit newsgathering methods.

The policy on the prosecution of journalists will include a public interest defence for journalism that uncovers a miscarriage of justice. The CPS said that the potential public interest defence of revealing miscarriages of justice would be balanced against considerations including whether the journalist used threats or intimidation, or put criminal proceedings in jeopardy.

"It would be prudent to have a policy that sets out in one place the factors that prosecutors will take into account when considering whether or not to prosecute journalists acting in the course of their work as journalists," Starmer said.

The Guido Fawkes blogger, Paul Staines, in evidenceon Wednesday, said he understood that the editor of the Sunday Mirror, Tina Weaver, had personally authorised hacking and blagging.

Staines said he was told by two journalists that Weaver "personally authorised and told them to hack, blag and do all that kind of stuff".

Staines added: "She knows all the bad things that have gone on under her rule. It's ridiculous."

Staines suggested that the now-defunct tabloid bought the photos to "take them off the market" as a favour to its former editor, Andy Coulson, who at the time was director of communications at No 10.

The blogger also told the inquiry that his home address had been discovered by a Daily Telegraph reporter, Gordon Rayner, and claimed that could only have been achieved by his details being leaked by a Land Registry employee. The Telegraph said that Staines and Rayner had never met. "We don't propose to be drawn into any dispute with him. However, as any journalist will know, the Land Registry is a public resource, available to all."

He claimed that Rayner had used Steve Whittamore, the private investigator convicted of illegally accessing data in 2005. Staines said that Rayner appeared in the information commissioner's Operation Motorman report into trade of data by newspapers 335 times.

"If this inquiry does not act as a catalyst for criminal prosecution for those journalists who have invaded people's privacy, on an industrial scale, I think you have failed," Staines told Lord Justice Leveson.

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